Abstract: A grounding device for connecting the body of a person to a ground point to drain off electrostatic charge from the body of the person. The device includes a conductive band worn on the wrist of the user, a connecting cable and sensing and indicating circuitry for verifying the electrical continuity of the grounding device.

Abstract: Apparatus for transporting elongated sample holders in a sample holder storage compartment past an operating station at which sample tubes contained in the sample holders may be removed and then returned to the sample holders. First and second parallel conveyors on opposite sides of the operating station drive the holders toward and away from the operating station. A lateral drive system engages the holders in longitudinal stop positions at opposite ends of the conveyors and drives them laterally between the conveyors to lateral stop positions, one of the holders during lateral movement being driven into and away from an operative position at the operating station. Encoded labels are displayed on each sample holder for indicating the incremental spacing between the sample tubes carried in the sample holder.

Abstract: A rotor adapted for containing a plurality of sample tubes and for retaining the contents of such tubes if any should rupture while in the rotor. The rotor includes an upper shell and a lower shell connected by a central hub interposed therebetween. Provision is made for coupling the hub to a drive shaft. The upper shell has a substantially frustoconical shape and a recessed top surface. The top surface has a form generally corresponding to the interior of an inverted frustum. A plurality of sample tubes are disposed in a circular locus in the top of the rotor. The lower shell of the rotor has a bottom formed with upturned inwardly sloping conical sides. The sides are disposed such that their uppermost portion is proximate the upper shell. In the event that one or more tubes ruptures while in the rotor, the contents will be retained in the lower shell rather than spilling into the rotor chamber.

Abstract: A variable slip drive system for driving a variable speed induction motor. The system includes a tachometer for providing a signal proportional to the speed of the motor and a slip oscillator. The output of the tachometer and slip oscillator are combined by a motor drive oscillator to provide a motor drive signal. The frequency of the motor drive signal equals the tachometer signal, less the frequency of the slip signal. The motor drive signal is converted into a proportional, three-phase, high power signal for powering the motor. The frequency of the slip signal is controlled so as to be proportional to the motor speed as a means of optimizing the motor's performance.

Abstract: A torque-transmitting connector is disclosed which fits between a spindle and the walls of a bore in a rotating member. The connector includes a sleeve encircling the spindle and two flanges located at its opposite ends. Each flange is initially frustoconical, and is forced into substantially a disc shape to grip the spindle and the wall of the bore. The flange at the bottom of the bore is flattened first by a small diameter punch acting against the other end of the sleeve; and the other flange is then flattened by an annular punch encircling the small diameter punch.

Abstract: Apparatus for transporting elongated sample holders in a sample holder storage compartment past an operating station at which sample tubes contained in the sample holders may be removed and then returned to the sample holders. First and second parallel conveyors on opposite sides of the operating station drive the holders toward and away from the operating station. Lateral drive means engage the holders in longitudinal stop positions at opposite ends of the conveyors and drive them laterally between the conveyors to lateral stop positions, one of the holders during lateral movement being driven into and away from an operative position at the operating station. Encoded label means are displayed on each sample holder for indicating the incremental spacing between the sample tubes carried in the sample holder.

Abstract: A process for generating high resolution conductive patterns on an insulating substrate. A photosensitive resin coating applied to the surface of a substrate is exposed to a suitable light source through a mask. The unexposed portion of the coating defines the desired conductive pattern which is then coated with a low temperature melting glass powder. The substrate is fired to sinter the glass pattern and fuse it to the substrate. The substrate is then coated with a slurry of fine metal particles suspended in a volatilizable carrier. The substrate is again fired to sinter the metal into a united mass and causing it to fuse only with the low temperature melting glass pattern. The unadhered portions of the metal coating are removed by a washing operation. An exclusively metallic layer is thereby formed on a high resolution glass pattern intermediate layer supported by the substrate.

Abstract: The present invention is directed to a shell type centrifuge rotor formed as a frustoconical shell having a circular rim adjacent at least one end thereof. The lower end of the shell is open, whereas the upper end has a conical recess and a central opening. The recess has an inverted frustoconical sidewall, with a plurality of apertures equally spaced therein and disposed an equal distance from the central opening.A tube holder is mounted in each of the apertures for receiving a centrifuge test tube. The tube holder has a flange configured so as to fit the surface contour of the conical recess so that the flange fully contacts the wall of the conical recess when the tube holder is mounted in the aperture. A hub is mounted in the central opening of the conical recess and couples the frustoconical shell to the centrifuge drive shaft. Means are secured to the hub for partially enclosing the lower end of the frustoconical shell to reduce the windage of the rotor to a predetermined level.

Abstract: The present invention is directed to a circuit for generating a voltage for compensating the output of a thermocouple. The circuit provides a compensating voltage to enable the thermocouple to be operated with its reference junction at ambient temperature. The compensation voltage varies linearly with changes in the ambient temperature and passes through zero volts at 0-20 C. The compensation voltage is generated by combining a temperature variable voltage developed across one or more semiconductor junctions with a constant voltage of opposite polarity.

Abstract: A liner for use in a centrifuge rotor bucket for converting a single cavity bucket into a multicavity bucket to provide separate support for at least two flexible fluid sample containers. The liner has a separation ridge which defines at least two areas in the liner, but allows maximum space for receipt of the flexible containers. Handle means are attached to the liner to provide ease in the removal and insertion of the liner into the rotor bucket.

Abstract: A safety latching apparatus for a cover of a machine enclosing a round rotatable member. The apparatus includes a latch member, and an elongated flexible control element for sensing the motion of the rotatable member to automatically prevent opening of the cover when the member is rotating. The control element is movable longitudinally so that one of its ends can be brought into contact with the rotatable member and the other end connected to a latching mechanism located adjacent the machine cover. When the rotatable member is stationary, the end of the control element brought into contact with it remains generally rigid to a force in the longitudinal direction allowing the latch member to move to an unlocked position.

Abstract: A cover having a free-turning knob in its center for use on the rotor of a centrifuge. The knob includes tool means for coupling the knob with a threaded fastener securing the rotor to a drive shaft. Thus, when the cover is positioned on the rotor, the threaded fastener securing the rotor can be tightened or loosened by a turning of the knob. The rotor can thereby be removed and replaced without the use of external tools.

Abstract: A switching voltage regulator is provided for coupling a source of AC potential to a DC load. Thyristor full wave rectifier means provide a source of DC potential which is connected to the load through an inductance in series with the load. The input of the inductance is shunted by a commutating diode which provides a path for the inductive current when the thyristor means are in the nonconducting phase of their operating cycle. Circuit means are provided to reverse bias the commutating diode in advance of each conduction cycle of the thyristor means. As a consequence, the level of RFI conducted to the AC power line is significantly reduced.

Abstract: A swinging bucket centrifuge rotor having a plurality of cavities spaced about its vertical axis and extending entirely through the rotor. Each cavity is adapted to receive a bucket supported by a hanger rod. The mounting of the bucket is such that the bucket can pivot or swing from a vertical to a horizontal position during operation. Each cavity is provided with a slot, which extends along the underside of the rotor, from the cavity to the periphery of the rotor. The slot has an upper surface adapted to receive the bucket when the bucket is in the horizontal position. A pair of opposed grooves extend partway down the wall of the cavity whereby the ends of the grooves each form a ledge to support an end of the hanger rod by which the bucket is pivotally suspended.

Abstract: A centrifuge rotor is provided which has a circumferential wall and a plurality of spaced arms which radiate outward from the center to the circumferential wall. A plurality of buckets are mounted on the rotor, one between each arm. Each bucket has two outwardly extending pivot pins situated on a common axis. A plurality of hangers are mounted in the spaced arms of the rotor. Each hanger comprises an elongated housing containing an opening which is transverse to the longitudinal dimension of the housing for receiving the pivot pin of a bucket. A longitudinal bore intersects the opening and contains a spring for exerting a clamping force on the pivot pin when the rotor is stopped. This prevents the bucket from rocking when being loaded or unloaded, but does not prevent the bucket from pivoting to a horizontal position when the rotor is rotating, nor does it prevent the bucket from resuming a vertical position when the rotor is stopped.

Abstract: A centrifuge rotor and sample containers for reorienting gradients and separating the components of a sample. The rotor contains a plurality of cylindrical recesses equally spaced about its rotational axis. The recesses are open at the top and have a concave hemispherical bottom. A cylindrical plug member is positioned in each of the recesses, and the lowermost end of the cylindrical plug member is formed in the shape of a concave hemisphere. A sample container in the shape of a hollow sphere is positioned between the hemisphere of the cylindrical plug member and the hemisphere of the recess bottom, and means are provided to retain the cylindrical plug member in the recess. The symmetry of the hemispherically shaped sample container is advantageous for minimizing any disturbance to a gradient during reorientation. In another embodiment, a centrifuge rotor is provided which is adapted for fixed angle centrifugation with hemispherical sample containers.

Abstract: A transparent tube for use in the cavity of the rotor of a high speed centrifuge. The tube is penetrable at its bottom end by a needle of a hypodermic syringe. The tube is open at the top and has a rounded bottom with an opening forming a passageway therein. A recess forming a shoulder co-axial with the passageway is provided both on the inner side and the outer side of the tube. A resilient plug having flanges at each end provides a tight fitting closure for the passageway and recesses.

Abstract: The present invention provides a centrifuge rotor adapted for continuous separation of specific particles from mixed populations thereof by a process of centrifugal elutriation. In the rotor, elutriation cells abut a central spindle having fluid carrying means, and thereby eliminate intermediate conduits and seals therefor, thus reducing the likelihood of leakage because of faulty aperture registration or failure of the sealing means.

Abstract: In accordance with the present invention, there is provided an air driven centrifuge having an access door to a rotor chamber housing a rotor seat and a rotor having a plurality of turbine flutes formed in the underside thereof. Air jet means in the rotor seat are provided for supporting and spinning the rotor on an air cushion in the chamber. Means are provided to prevent the opening of the access door when pressurized air is supplied to the air jets, and means are provided to delay for a predetermined period, the opening of the door after the supply of pressurized air to the air jets is discontinued.

Abstract: In a digital test instrument such as a digital ohmmeter for measuring and digitally displaying the resistance of an unknown circuit element, there is included an electrical continuity tester coupled to the input of the digital ohmmeter for instantaneously and digitally indicating electrical continuity. Connection of the electrical continuity tester to the input of the digital ohmmeter is achieved in a manner such as to not overload or otherwise affect the accuracy of the resistance measurement.